NEW YORK (AP) — Wall Street’s worst fears came to pass Monday, when the government’s financial bailout plan failed in Congress and stocks plunged precipitously — hurtling the Dow Jones industrials down nearly 780 points in their largest one-day point drop ever. Credit markets, whose turmoil helped feed the stock market’s angst, froze up further amid the growing belief that the country is headed into a spreading credit and economic crisis. Stunned traders on the floor of the New York Stock Exchange, their faces tense and mouths agape, watched on TV screens as the House voted down the plan in mid-afternoon, and as they saw stock prices tumbling on their monitors. Activity on the floor became frenetic as the “sell” orders blew in.